The invention deals with the field of fertilizer handling and in particular with systems for distributing and dispensing fertilizer.
Demand for fertilizer is seasonal as the majority of fertilizer is applied at seeding or immediately before, usually over the course of four to six weeks out of a year. This very intense but short demand is difficult for fertilizer distributors to economically manage since it requires high labour input for a short period of time. It is difficult to find workers, as in farming areas there is a high labour demand at that time of year from everyone in agriculture.
Demand is increasing for blended fertilizers as more farmers soil test to determine what combination of nutrients is right for a particular field. They need to obtain the proper blend of different fertilizers so that the particular nutrients may be applied. Today""s farmers therefore need more different blends and correspondingly smaller quantities of each blend. This makes on farm storage difficult with the result that more fertilizer is picked up by farmers as they apply it, further increasing the peak demand.
With consolidation of all kinds of rural services, including fertilizer dealers, in the larger towns, there are increased distances to the farms where the fertilizer is required. This puts a stress on the farmers"" resources as well since more time and expense is involved in going to pick up the required fertilizer at a time when labour is usually already stretched to its limits.
Granular standard fertilizers are manufactured in more or less standard nutrient amounts and delivered to fertilizer dealers. The amount of a given nutrient in a standard fertilizer is designated by a number indicating the percentage of nutrient contained. The numbers are standardized, in Western Canada at least, such that the percentage of nitrogen is first, then phosphorus, then potassium and then sulfur.
For example a standard phosphate fertilizer may have an analysis of 11-52-0 meaning in 100 pounds of product there will be 11 pounds of nitrogen, 52 pounds of phosphorus and no potassium or sulfur. A standard nitrogen fertilizer may have an analysis of 46-0-0 meaning in 100 pounds of product there will be 46 pounds of nitrogen, no phosphorus, no potassium and no sulfur. A standard potassium fertilizer may have an analysis of 0-0-60 meaning in 100 pounds of product there will be no nitrogen, no phosphorus, 60 pounds of potassium and no sulfur. A standard sulphur fertilizer may have an analysis of 21-0-0-24 meaning in 100 pounds of product there will be 21 pounds of nitrogen, no phosphorus, no potassium and 24 pounds of sulfur.
The standard fertilizers are blended proportionately so that a farmer can apply, for example, 10 pounds of nitrogen, 10 pounds of phosphorous, 10 pounds of potassium and 5 pounds of sulfur on a field.
To calculate the blend, we start with the following required ingredients:
We need 19.23 pounds/acre of 11-52-0 to apply 10 pounds/acre of phosphorus (19.23xc3x9752%)
We need 16.67 pounds/acre of 0-0-60 to apply 10 pounds/acre of potassium (16.67xc3x9760%)
We need 20.83 pounds/acre of 21-0-0-24 to apply 5 pounds/acre of sulfur (20.83xc3x9724%)
Applying the above will, because of the nitrogen present in the 11-52-0 and 21-0-0-24 standard fertilizers, result in the application of the following nutrients per acre:
The nitrogen amount is short 3.47 pounds, so the single nutrient standard fertilizer 46-0-0 must be added to make up the shortage:
The proportions of each standard fertilizer in the blend is then as follows:
The blended fertilizer is identified by the identification number 15.55-15.55-15.55-7.75 which, when applied at 64.27 pounds/acre, will give the desired 10 pounds of nitrogen, 10 pounds of phosphorous, 10 pounds of potassium and 5 pounds of sulfur per acre.
Other standard fertilizers may contain other nutrients, and so the blending calculation can become quite complex. Computers are commonly used to calculate the blended fertilizer and application rate thereof that is required to apply a given amount of each nutrient and the proper proportions of standard fertilizers needed to achieve the blend.
For granular fertilizer, the correct individual amounts can be placed in a weighing batch blender, such as a rotating drum blender, where they are mixed into a substantially homogeneous blend. The weighing batch blender indicates the weight of fertilizer in the blender so that the operator can put in the proper amount of each standard fertilizer.
Alternatively the granular fertilizer can be continuously blended by adding the correct proportional amounts to a mixing conveyor, such as an auger, carrying the fertilizer to the customer""s truck. A system for continuous blending is disclosed in U.S. Pat. No. 4,527,245 to Axelson, Jr. et al.
The benefits of liquid fertilizer are becoming more accepted and recognized by farmers, with the resulting increase in demand. Liquid standard fertilizers similarly are manufactured in standard nutrient amounts and delivered to dealers. For example a liquid phosphate fertilizer will have an analysis of 10-34-0 meaning in 100 pounds of product there will be 10 pounds of nitrogen, 34 pounds of phosphorus and no potassium. A liquid nitrogen fertilizer will have an analysis of 28-0-0 meaning in 100 pounds of product there will be 28 pounds of nitrogen, no phosphorus and no potassium. Liquid fertilizer is easily blended by simply adding the correct individual amounts to a tank where the liquid will essentially mix itself.
Liquid blended fertilizer is identified in the same way as granular blended fertilizer, with the percentage of each nutrient given in the same order as for granular.
As can be seen from comparing the nutrients in liquid and granular fertilizer, the liquid requires substantially higher quantities of material to be moved for the same amount of nutrients. For a busy farmer, hauling these larger quantities of liquid fertilizer long distances can be a real problem.
Satellite fertilizer distribution sites could be located in areas remote from the main dealer and convenient to the farmer consumers, however the expense of manning the sites is prohibitive. The operator of a present fertilizer blending plant must be skilled in calculation of blends, or at least in operating a computer to calculate same, as well as in operating the equipment required to blend and load the fertilizer. Un-skilled labour is therefore not a feasible option, as a miscalculation can result in application of the wrong nutrients and costly crop losses. As well, farmers expect to be able to pick up fertilizer from early morning to late at night, which could require two shifts of labour to cover the desired operating hours at the site.
It is an object of the present invention to provide a system and method for dispensing blended fertilizer that reduces the chances for errors in blending by the person dispensing the fertilizer.
It is a further object of the present invention to provide such a system and method that may be used at an unmanned dispensing site remote from the dealer site.
The invention accomplishes these objects providing in one aspect a method of dispensing blended fertilizer to a customer at a dispensing site, said blended fertilizer blended from a plurality of standard fertilizer ingredients by a blending and dispensing apparatus, said method comprising the following steps: entering the blend of standard fertilizer ingredients required to provide said customer""s desired nutrients into a database identified with said customer, wherein said database is readable by a dispensing site based computer; providing an identifier to a customer, said identifier recognizable by said site based computer; presenting said identifier to said site based computer and entering into said site based computer the desired quantity of blended fertilizer to be dispensed; said site based computer then operating said blending and dispensing apparatus to dispense the desired quantity of blended fertilizer to the customer in accordance with said customer""s desired fertilizer blend stored in the database.
The dispensing site could be remote from the dealer location allowing the customer around the clock access to blended fertilizer. The dealer and customer determine the amount of each nutrient required per acre for a given field and the dealer uses existing software, such as TRONIA(trademark), to determine the blend required.
The blend is entered on the database and identified as one of the blended fertilizers available to the customer. There will likely be two or more blended fertilizers associated with each customer, and each blend will be entered into the database identified with that customer.
The customer, when attending the site to pick up fertilizer, will present his identifier, conveniently a coded card, to the site based computer. The customer will then be presented with a choice, on a small screen or the like, of the blended fertilizers available to him, and he will select, by pressing a numbered button or the like, the blended fertilizer that he wants to get and also will select the quantity to be dispensed. This method will reduce the possibility of choosing the wrong blend, as only pre-selected blends are available. The method allows for operation of a remote unmanned site. The customer would have only a few choices which could be identified with certain fields.
Alternatively the system could operate so that only one blended fertilizer could be available at any one time, so that the farmer would call the dealer and tell him which blended fertilizer was to be available. The dealer would then alter the database to make the requested blend available. This might be preferred where un-skilled or un-informed labour is employed to pick up the blended fertilizer, as only the quantity would be selected, with the farmer, through the dealer, selecting the blend.
It is also possible to allow the customer access to the system to create his own blends at the dispensing site, however it is contemplated that only rarely would this be advisable as the possibilities for error are substantial.
The site based computer will then dispense the proper blended fertilizer by controlling the operation of the blending and dispensing apparatus, which could be any known system. The method could be used for liquid or granular fertilizer.
In a second aspect the invention provides a method of dispensing liquid blended fertilizer to a customer""s tank at a dispensing site, said liquid blended fertilizer dispensed from a plurality of standard fertilizer ingredients by a dispensing apparatus, said method comprising the following steps: entering the blend of standard liquid fertilizer ingredients required to provide said customer""s desired blended fertilizer into a database identified with said customer, wherein said database is readable by a dispensing site based computer; providing an identifier to a customer, said identifier recognizable by said site based computer; presenting said identifier to said site based computer and entering into said site based computer the desired quantity of blended liquid fertilizer to be dispensed; said site based computer then calculating the quantity of each liquid standard fertilizer ingredient required in the selected quantity of blended liquid fertilizer and then operating said dispensing apparatus to dispense the required amount of each liquid standard fertilizer ingredient into said tank one ingredient at a time.
Liquid fertilizer may be blended in the customers tank by adding the standard fertilizer ingredients one at a time, thus simplifying the required apparatus, as the dispensing and blending apparatus may become simply a dispensing apparatus, which could comprise a pump, a valve and a meter which would indicate to the site based computer the quantity of each liquid standard fertilizer ingredient dispensed.
In a third aspect the invention provides an apparatus for dispensing granular blended fertilizer to a customer at a dispensing site, said blended fertilizer blended from a plurality of granular standard fertilizer ingredients, said system comprising a customer identifier; a site based computer operatively connected to a database containing at least one fertilizer blend identified with said customer, said site based computer programmed to identify said customer and said blend when presented with said customer identifier and to calculate the weight of each standard fertilizer required for the amount of blended fertilizer entered by said customer; a weighing batch blender operatively connected to said site based computer such that the weight of fertilizer in said weighing batch blender may be read by said site based computer; means to dispense said blended fertilizer to said customer from said weighing batch blender, said means to dispense operatively connected to said site based computer; means to selectively convey said standard fertilizer ingredients to said weighing batch blender one at a time, said means to selectively convey operatively connected to said site based computer; said site based computer programmed to convey the correct individual weight of each standard fertilizer to said weighing batch blender, to then operate said blender for a suitable time to blend said standard fertilizers into said blended fertilizer and to then operate said means to dispense said blended fertilizer to said customer and then to store the quantity of blended fertilizer dispensed to said customer in said database.
The means to dispense the blended fertilizer to the customer could convenveniently comprise a dispensing conveyor. The means to selectively convey standard fertilizer ingredients to the weighing batch blender one at a time could conveniently comprise a plurality of transfer conveyors, each transfer conveyor operatively connected to a storage container containing a quantity of one granular standard fertilizer ingredient, each transfer conveyor operative to convey one of the granular standard fertilizer ingredients to the batch blender when activated by said site based computer.
The apparatus could be operated by an unskilled worker or by the customer himself at an unmanned site. The available blends are limited to those entered into the database by the dealer.
A dealer computer could be linked to the site based computer such that the database may be revised by instructions received from the dealer computer and such that the quantity of fertilizer dispensed to a selected customer may be transmitted to the dealer computer.
The method or apparatus could be set up so that the customer must activate a dead-man switch before the site based computer will operate the apparatus to dispense blended fertilizer. At an unmanned site, this would be a desirable safety feature.
The database could store the quantity of blended fertilizer delivered to a customer which information could be used for billing or other purposes. When dispensing is complete, the site based computer could print a report of the quantity and blend of fertilizer dispensed for the customer""s records. Conveniently the quantity of blended fertilizer to be applied per acre could be printed on the report for the customer""s reference, as could any other related information.